
I made these from 3mm plate for an engine builder – described elsewhere on this forum. Engraving used a 1mm slot drill (carbide). I carved out a lot of brass to give 1.5mm deep relief letters.
If you use an ordinary engraving cutter, it's best for inlayed letters, or ones done in outline. I think that the cutter form is basically conical at 30 or 60 degrees but with the point truncated so the flat tip diameter is (in your example) .002 (units? Inches I would guess.). So that's the thinnest line you can cut, then the additional thickness is set by the depth of cut and the cone angle – a bit of trigonometry would give that.
If you don't have engraving software I can recommend F-Engrave – it's free and versatile, does multi-line, and can V-carve an image (as used for the example above in fact).